<?php
/* vim: set expandtab sw=4 ts=4 sts=4: */
/**
 *
 * @version $Id: zip.lib.php 11986 2008-11-24 11:05:40Z nijel $
 * @package phpMyAdmin
 */

/**
 * Zip file creation class.
 * Makes zip files.
 *
 * Based on :
 *
 *  http://www.zend.com/codex.php?id=535&single=1
 *  By Eric Mueller <eric@themepark.com>
 *
 *  http://www.zend.com/codex.php?id=470&single=1
 *  by Denis125 <webmaster@atlant.ru>
 *
 *  a patch from Peter Listiak <mlady@users.sourceforge.net> for last modified
 *  date and time of the compressed file
 *
 * Official ZIP file format: http://www.pkware.com/appnote.txt
 *
 * @access  public
 * @package phpMyAdmin
 */
class zipfile {
  /**
   * Array to store compressed data
   *
   * @var  array    $datasec
   */
  var $datasec = array();

  /**
   * Central directory
   *
   * @var  array    $ctrl_dir
   */
  var $ctrl_dir = array();

  /**
   * End of central directory record
   *
   * @var  string   $eof_ctrl_dir
   */
  var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";

  /**
   * Last offset position
   *
   * @var  integer  $old_offset
   */
  var $old_offset = 0;

  /**
   * Converts an Unix timestamp to a four byte DOS date and time format (date
   * in high two bytes, time in low two bytes allowing magnitude comparison).
   *
   * @param  integer  the current Unix timestamp
   *
   * @return integer  the current date in a four byte DOS format
   *
   * @access private
   */
  function unix2DosTime($unixtime = 0) {
    $timearray = ($unixtime == 0) ? getdate() : getdate($unixtime);

    if ($timearray['year'] < 1980) {
      $timearray['year'] = 1980;
      $timearray['mon'] = 1;
      $timearray['mday'] = 1;
      $timearray['hours'] = 0;
      $timearray['minutes'] = 0;
      $timearray['seconds'] = 0;
    } // end if

    return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) |
      ($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
  } // end of the 'unix2DosTime()' method


  /**
   * Adds "file" to archive
   *
   * @param  string   file contents
   * @param  string   name of the file in the archive (may contains the path)
   * @param  integer  the current timestamp
   *
   * @access public
   */
  function addFile($data, $name, $time = 0) {
    $name = str_replace('\\', '/', $name);

    $dtime = dechex($this->unix2DosTime($time));
    $hexdtime = '\x' . $dtime[6] . $dtime[7]
      . '\x' . $dtime[4] . $dtime[5]
      . '\x' . $dtime[2] . $dtime[3]
      . '\x' . $dtime[0] . $dtime[1];
    eval('$hexdtime = "' . $hexdtime . '";');

    $fr = "\x50\x4b\x03\x04";
    $fr .= "\x14\x00"; // ver needed to extract
    $fr .= "\x00\x00"; // gen purpose bit flag
    $fr .= "\x08\x00"; // compression method
    $fr .= $hexdtime; // last mod time and date

    // "local file header" segment
    $unc_len = strlen($data);
    $crc = crc32($data);
    $zdata = gzcompress($data);
    $zdata = substr(substr($zdata, 0, strlen($zdata) - 4), 2); // fix crc bug
    $c_len = strlen($zdata);
    $fr .= pack('V', $crc); // crc32
    $fr .= pack('V', $c_len); // compressed filesize
    $fr .= pack('V', $unc_len); // uncompressed filesize
    $fr .= pack('v', strlen($name)); // length of filename
    $fr .= pack('v', 0); // extra field length
    $fr .= $name;

    // "file data" segment
    $fr .= $zdata;

    // "data descriptor" segment (optional but necessary if archive is not
    // served as file)
    // nijel(2004-10-19): this seems not to be needed at all and causes
    // problems in some cases (bug #1037737)
    //$fr .= pack('V', $crc);                 // crc32
    //$fr .= pack('V', $c_len);               // compressed filesize
    //$fr .= pack('V', $unc_len);             // uncompressed filesize

    // add this entry to array
    $this->datasec[] = $fr;

    // now add to central directory record
    $cdrec = "\x50\x4b\x01\x02";
    $cdrec .= "\x00\x00"; // version made by
    $cdrec .= "\x14\x00"; // version needed to extract
    $cdrec .= "\x00\x00"; // gen purpose bit flag
    $cdrec .= "\x08\x00"; // compression method
    $cdrec .= $hexdtime; // last mod time & date
    $cdrec .= pack('V', $crc); // crc32
    $cdrec .= pack('V', $c_len); // compressed filesize
    $cdrec .= pack('V', $unc_len); // uncompressed filesize
    $cdrec .= pack('v', strlen($name)); // length of filename
    $cdrec .= pack('v', 0); // extra field length
    $cdrec .= pack('v', 0); // file comment length
    $cdrec .= pack('v', 0); // disk number start
    $cdrec .= pack('v', 0); // internal file attributes
    $cdrec .= pack('V', 32); // external file attributes - 'archive' bit set

    $cdrec .= pack('V', $this->old_offset); // relative offset of local header
    $this->old_offset += strlen($fr);

    $cdrec .= $name;

    // optional extra field, file comment goes here
    // save to central directory
    $this->ctrl_dir[] = $cdrec;
  } // end of the 'addFile()' method


  /**
   * Dumps out file
   *
   * @return  string  the zipped file
   *
   * @access public
   */
  function file() {
    $data = implode('', $this->datasec);
    $ctrldir = implode('', $this->ctrl_dir);

    return
      $data .
      $ctrldir .
      $this->eof_ctrl_dir .
      pack('v', sizeof($this->ctrl_dir)) . // total # of entries "on this disk"
      pack('v', sizeof($this->ctrl_dir)) . // total # of entries overall
      pack('V', strlen($ctrldir)) . // size of central dir
      pack('V', strlen($data)) . // offset to start of central dir
      "\x00\x00"; // .zip file comment length
  } // end of the 'file()' method

} // end of the 'zipfile' class
?>
